The luxury residential real estate market has soared to unprecedented heights in the past year, in terms of both price tags and building heights. But none of today’s $100 million penthouses rest atop a quintessential New York building. That will change next year, when new condominiums at the Woolworth Building hit the market.

Last August, The New York Times reported that Alchemy Properties had paid $68 million in a deal with building owners the Witkoff Group and Cammeby’s International to turn the top 30 floors of the 100-year-old landmark building into 40 luxury apartments—including a trophy penthouse spanning a whopping five stories at the top.

The Woolworth Building

“The project was brought to us sometime in April of last year,” said Kenneth Horn, the president and founder of Alchemy. “We’d looked at it many, many years ago, but it was more seriously brought to us last year, and quietly, because it was not a mass-marketed project.” Mr. Horn counted 55 people at the closing last summer, which speaks to the magnitude of the deal despite its relatively swift completion.

While Alchemy’s plans proceeded quickly, the idea of condos at the Woolworth Building has been floated since 2000 when Steve Witkoff presented it. (Plans were shelved after 9/11.) Since then, the residential population of lower Manhattan has nearly tripled, to about 60,000 people, and high-profile apartment towers like 8 Spruce Street have redefined the skyline.

Alchemy’s purchase was well-timed, but not without hitches. The fact that Alchemy was only buying the upper portion of the 57-story building complicated matters. “Separately buying a condominium interest rather than a whole building is a complicated and sophisticated transaction,” Mr. Horn said. Specifically, Alchemy had to “go vertical” to get heat, electricity and plumbing from the basement mechanical systems.

Also, any work on a landmarked building must be done delicately. Alchemy is beginning formal meetings with the Landmarks Preservation Commission, but Mr. Horn emphasizes that any changes to the Woolworth Building’s terra cotta exterior will be minimal and unnoticeable from ground level. “We are 100 percent going to be respectful,” he said.

Interior work, meanwhile, will be done with an eye toward appealing to contemporary apartment shoppers with Downtown tastes. “The goal here is to have modern flair but also to work with the building, not change it,” Mr. Horn said. He added that it was premature to discuss pricing or apartment sizes, but did say sales would start around the first quarter of 2014. The Times article speculated that rents could reach $3,000 per square foot.

Many of Manhattan’s trophy apartments have recently gone to foreign oligarchs. Mr. Horn expects an array of buyers to show interest in the Woolworth Building. “I think it will attract a New York and an international crowd,” he said. “The views are probably better than at any other building in the city, and the property is an icon.”

The neighborhood is an additional draw, and one whose appeal should continue to grow. “Lower Manhattan has an entirely different feel than it did a decade ago,” Mr. Horn said. “I can’t think of another area in New York that’s going to go through such massive change over the next five years.”